Rules

Base rule

class hammurabi.rules.base.Rule(name: str, param: Any, preconditions: Iterable[hammurabi.preconditions.base.Precondition] = (), pipe: Optional[Rule] = None, children: Iterable[Rule] = ())

Abstract class which describes the bare minimum and helper functions for Rules. A rule defines what and how should be executed. Since a rule can have piped and children rules, the “parent” rule is responsible for those executions. This kind of abstraction allows to run both piped and children rules sequentially in a given order.

Example usage:

>>> from typing import Optional
>>> from pathlib import Path
>>> from hammurabi import Rule
>>> from hammurabi.mixins import GitMixin
>>>
>>> class SingleFileRule(Rule, GitMixin):
>>>     def __init__(self, name: str, path: Optional[Path] = None, **kwargs) -> None:
>>>         super().__init__(name, path, **kwargs)
>>>
>>>     def post_task_hook(self):
>>>         self.git_add(self.param)
>>>
>>>     @abstractmethod
>>>     def task(self) -> Path:
>>>         pass

Parameters

• name (str) – Name of the rule which will be used for printing

• param (Any) – Input parameter of the rule will be used as self.param

• preconditions (Iterable["Rule"]) – “Boolean Rules” which returns a truthy or falsy value

• pipe (Optional["Rule"]) – Pipe will be called when the rule is executed successfully

• children (Iterable["Rule"]) – Children will be executed after the piped rule if there is any

Warning

Preconditions can be used in several ways. The most common way is to run “Boolean Rules” which takes a parameter and returns a truthy or falsy value. In case of a falsy return, the precondition will fail and the rule will not be executed.

If any modification is done by any of the rules which are used as a precondition, those changes will be committed.

Attributes

OwnerChanged

class hammurabi.rules.attributes.OwnerChanged(name: str, path: Optional[pathlib.Path] = None, new_value: Optional[str] = None, **kwargs)

Change the ownership of a file or directory.

The new ownership of a file or directory can be set in three ways. To set only the user use new_value="username". To set only the group use new_value=":group_name" (please note the colon :). It is also possible to set both username and group at the same time by using new_value="username:group_name".

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, OwnerChanged
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         OwnerChanged(
>>>             name="Change ownership of nginx config",
>>>             path=Path("./nginx.conf"),
>>>             new_value="www:web_admin"
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

ModeChanged

class hammurabi.rules.attributes.ModeChanged(name: str, path: Optional[pathlib.Path] = None, new_value: Optional[int] = None, **kwargs)

Change the mode of a file or directory.

Supported modes:

Config option	Description
stat.S_ISUID	Set user ID on execution.
stat.S_ISGID	Set group ID on execution.
stat.S_ENFMT	Record locking enforced.
stat.S_ISVTX	Save text image after execution.
stat.S_IREAD	Read by owner.
stat.S_IWRITE	Write by owner.
stat.S_IEXEC	Execute by owner.
stat.S_IRWXU	Read, write, and execute by owner.
stat.S_IRUSR	Read by owner.
stat.S_IWUSR	Write by owner.
stat.S_IXUSR	Execute by owner.
stat.S_IRWXG	Read, write, and execute by group.
stat.S_IRGRP	Read by group.
stat.S_IWGRP	Write by group.
stat.S_IXGRP	Execute by group.
stat.S_IRWXO	Read, write, and execute by others.
stat.S_IROTH	Read by others.
stat.S_IWOTH	Write by others.
stat.S_IXOTH	Execute by others.

Example usage:

>>> import stat
>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, ModeChanged
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         ModeChanged(
>>>             name="Update script must be executable",
>>>             path=Path("./scripts/update.sh"),
>>>             new_value=stat.S_IXGRP | stat.S_IXGRP | stat.S_IXOTH
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Directories

DirectoryExists

class hammurabi.rules.directories.DirectoryExists(name: str, path: Optional[pathlib.Path] = None, **kwargs)

Ensure that a directory exists. If the directory does not exists, make sure the directory is created.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, DirectoryExists
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         DirectoryExists(
>>>             name="Create secrets directory",
>>>             path=Path("./secrets")
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

DirectoryNotExists

class hammurabi.rules.directories.DirectoryNotExists(name: str, path: Optional[pathlib.Path] = None, **kwargs)

Ensure that the given directory does not exists.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, DirectoryNotExists
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         DirectoryNotExists(
>>>             name="Remove unnecessary directory",
>>>             path=Path("./temp")
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

DirectoryEmptied

class hammurabi.rules.directories.DirectoryEmptied(name: str, path: Optional[pathlib.Path] = None, **kwargs)

Ensure that the given directory’s content is removed. Please note the difference between emptying a directory and recreating it. The latter results in lost ACLs, permissions and modes.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, DirectoryEmptied
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         DirectoryEmptied(
>>>             name="Empty results directory",
>>>             path=Path("./test-results")
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Files

FileExists

class hammurabi.rules.files.FileExists(name: str, path: Optional[pathlib.Path] = None, **kwargs)

Ensure that a file exists. If the file does not exists, make sure the file is created.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, FileExists
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         FileExists(
>>>             name="Create service descriptor",
>>>             path=Path("./service.yaml")
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

FilesExist

class hammurabi.rules.files.FilesExist(name: str, paths: Optional[Iterable[pathlib.Path]] = (), **kwargs)

Ensure that all files exists. If the files does not exists, make sure the files are created.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, FilesExist
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         FilesExist(
>>>             name="Create test files",
>>>             paths=[
>>>                 Path("./file_1"),
>>>                 Path("./file_2"),
>>>                 Path("./file_3"),
>>>             ]
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

FileNotExists

class hammurabi.rules.files.FileNotExists(name: str, path: Optional[pathlib.Path] = None, **kwargs)

Ensure that the given file does not exists. If the file exists remove it, otherwise do nothing and return the original path.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, FileNotExists
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         FileNotExists(
>>>             name="Remove unused file",
>>>             path=Path("./debug.yaml")
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

FilesNotExist

class hammurabi.rules.files.FilesNotExist(name: str, paths: Optional[Iterable[pathlib.Path]] = (), **kwargs)

Ensure that the given files does not exist. If the files exist remove them, otherwise do nothing and return the original paths.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, FilesNotExist
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         FilesNotExist(
>>>             name="Remove several files",
>>>             paths=[
>>>                 Path("./file_1"),
>>>                 Path("./file_2"),
>>>                 Path("./file_3"),
>>>             ]
>>>         ),
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

FileEmptied

class hammurabi.rules.files.FileEmptied(name: str, path: Optional[pathlib.Path] = None, **kwargs)

Remove the content of the given file, but keep the file. Please note the difference between emptying a file and recreating it. The latter results in lost ACLs, permissions and modes.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, FileEmptied
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         FileEmptied(
>>>             name="Empty the check log file",
>>>             path=Path("/var/log/service/check.log")
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Ini files

SectionExists

SectionNotExists

SectionRenamed

OptionsExist

OptionsNotExist

OptionRenamed

JSON files

JSONKeyExists

class hammurabi.rules.json.JSONKeyExists(name: str, path: Optional[pathlib.Path] = None, key: str = '', value: Union[None, list, dict, str, int, float] = None, **kwargs)

Ensure that the given key exists. If needed, the rule will create a key with the given name, and optionally the specified value. In case the value is set, the value will be assigned to the key. If no value is set, the key will be created with an empty value.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, JSONKeyExists
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         JSONKeyExists(
>>>             name="Ensure service descriptor has stack",
>>>             path=Path("./service.json"),
>>>             key="stack",
>>>             value="my-awesome-stack",
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Warning

Compared to hammurabi.rules.text.LineExists, this rule is NOT able to add a key before or after a target.

JSONKeyNotExists

class hammurabi.rules.json.JSONKeyNotExists(name: str, path: Optional[pathlib.Path] = None, key: str = '', **kwargs)

Ensure that the given key not exists. If needed, the rule will remove a key with the given name, including its value.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, JSONKeyNotExists
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         JSONKeyNotExists(
>>>             name="Ensure outdated_key is removed",
>>>             path=Path("./service.json"),
>>>             key="outdated_key",
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

JSONKeyRenamed

class hammurabi.rules.json.JSONKeyRenamed(name: str, path: Optional[pathlib.Path] = None, key: str = '', new_name: str = '', **kwargs)

Ensure that the given key is renamed. In case the key can not be found, a LookupError exception will be raised to stop the execution. The execution must be stopped at this point, because if other rules depending on the rename they will fail otherwise.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, JSONKeyRenamed
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         JSONKeyRenamed(
>>>             name="Ensure service descriptor has dependencies",
>>>             path=Path("./service.json"),
>>>             key="development.depends_on",
>>>             value="dependencies",
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

JSONValueExists

class hammurabi.rules.json.JSONValueExists(name: str, path: Optional[pathlib.Path] = None, key: str = '', value: Union[None, list, dict, str, int, float] = None, **kwargs)

Ensure that the given key has the expected value(s). In case the key cannot be found, a LookupError exception will be raised to stop the execution.

This rule is special in the way that the value can be almost anything. For more information please read the warning below.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, JSONValueExists
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         JSONValueExists(
>>>             name="Ensure service descriptor has dependencies",
>>>             path=Path("./service.json"),
>>>             key="development.dependencies",
>>>             value=["service1", "service2", "service3"],
>>>         ),
>>>         # Or
>>>         JSONValueExists(
>>>             name="Add infra alerting to existing alerting components",
>>>             path=Path("./service.json"),
>>>             key="development.alerting",
>>>             value={"infra": "#slack-channel-2"},
>>>         ),
>>>         # Or
>>>         JSONValueExists(
>>>             name="Add support info",
>>>             path=Path("./service.json"),
>>>             key="development.supported",
>>>             value=True,
>>>         ),
>>>         # Or even
>>>         JSONValueExists(
>>>             name="Make sure that no development branch is set",
>>>             path=Path("./service.json"),
>>>             key="development.branch",
>>>             value=None,
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Warning

Since the value can be anything from None to a list of lists, and rule piping passes the 1st argument (path) to the next rule the value parameter can not be defined in __init__ before the path. Hence the value parameter must have a default value. The default value is set to None, which translates to the following:

Using the JSONValueExists rule and not assigning value to value parameter will set the matching key’s value to None` by default in the document.

JSONValueNotExists

class hammurabi.rules.json.JSONValueNotExists(name: str, path: Optional[pathlib.Path] = None, key: str = '', value: Union[str, int, float] = None, **kwargs)

Ensure that the key has no value given. In case the key cannot be found, a LookupError exception will be raised to stop the execution.

Compared to hammurabi.rules.json.JSONValueExists, this rule can only accept simple value for its value parameter. No list, dict, or None can be used.

Based on the key’s value’s type if the value contains (or equals for simple types) value provided in the value parameter the value is:

1. Set to None (if the key’s value’s type is not a dict or list)

2. Removed from the list (if the key’s value’s type is a list)

3. Removed from the dict (if the key’s value’s type is a dict)

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, JSONValueNotExists
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         JSONValueNotExists(
>>>             name="Remove decommissioned service from dependencies",
>>>             path=Path("./service.json"),
>>>             key="development.dependencies",
>>>             value="service4",
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Operations

Moved

class hammurabi.rules.operations.Moved(name: str, path: Optional[pathlib.Path] = None, destination: Optional[pathlib.Path] = None, **kwargs)

Move a file or directory from “A” to “B”.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, Moved
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         Moved(
>>>             name="Move pyproject.toml to its place",
>>>             path=Path("/tmp/generated/pyproject.toml.template"),
>>>             destination=Path("./pyproject.toml"),  # Notice the rename!
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Renamed

class hammurabi.rules.operations.Renamed(name: str, path: Optional[pathlib.Path] = None, new_name: Optional[str] = None, **kwargs)

This rule is a shortcut for hammurabi.rules.operations.Moved. Instead of destination path a new name is required.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, Renamed
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         Renamed(
>>>             name="Rename pyproject.toml.bkp",
>>>             path=Path("/tmp/generated/pyproject.toml.bkp"),
>>>             new_name="pyproject.toml",
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Copied

class hammurabi.rules.operations.Copied(name: str, path: Optional[pathlib.Path] = None, destination: Optional[pathlib.Path] = None, **kwargs)

Ensure that the given file or directory is copied to the new path.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, Copied
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         Copied(
>>>             name="Create backup file",
>>>             path=Path("./service.yaml"),
>>>             destination=Path("./service.bkp.yaml")
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Templates

TemplateRendered

class hammurabi.rules.templates.TemplateRendered(name: str, template: Optional[pathlib.Path] = None, destination: Optional[pathlib.Path] = None, context: Optional[Dict[str, Any]] = None, **kwargs)

Render a file from a Jinja2 template. In case the destination file not exists, this rule will create it, otherwise the file will be overridden.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, TemplateRendered
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         TemplateRendered(
>>>             name="Create gunicorn config from template",
>>>             template=Path("/tmp/templates/gunicorn.conf.py"),
>>>             destination=Path("./gunicorn.conf.py"),
>>>             context={
>>>                 "keepalive": 65
>>>             },
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Warning

This rule requires the templating extra to be installed.

Text files

LineExists

class hammurabi.rules.text.LineExists(name: str, path: Optional[pathlib.Path] = None, text: Optional[str] = None, target: Optional[str] = None, position: int = 1, respect_indentation: bool = True, ensure_trailing_newline: bool = False, **kwargs)

Make sure that the given file contains the required line. This rule is capable for inserting the expected text before or after the unique target text respecting the indentation of its context.

The default behaviour is to insert the required text exactly after the target line, and respect its indentation. Please note that text``and ``target parameters are required.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, LineExists, IsLineNotExists
>>>
>>> gunicorn_config = Path("./gunicorn.conf.py")
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         LineExists(
>>>             name="Extend gunicorn config",
>>>             path=gunicorn_config,
>>>             text="keepalive = 65",
>>>             target=r"^bind.*",
>>>             preconditions=[
>>>                 IsLineNotExists(path=gunicorn_config, criteria=r"^keepalive.*")
>>>             ]
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Note

The indentation of the target text will be extracted by a simple regular expression. If a more complex regexp is required, please inherit from this class.

LineNotExists

class hammurabi.rules.text.LineNotExists(name: str, path: Optional[pathlib.Path] = None, text: Optional[str] = None, **kwargs)

Make sure that the given file not contains the specified line.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, LineNotExists
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         LineNotExists(
>>>             name="Remove keepalive",
>>>             path=Path("./gunicorn.conf.py"),
>>>             text="keepalive = 65",
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

LineReplaced

class hammurabi.rules.text.LineReplaced(name: str, path: Optional[pathlib.Path] = None, text: Optional[str] = None, target: Optional[str] = None, respect_indentation: bool = True, **kwargs)

Make sure that the given text is replaced in the given file.

The default behaviour is to replace the required text with the exact same indentation that the target line has. This behaviour can be turned off by setting the respect_indentation parameter to False. Please note that text and target parameters are required.

Example usage:

>>> from pathlib import Path
>>> from hammurabi import Law, Pillar, LineReplaced
>>>
>>> example_law = Law(
>>>     name="Name of the law",
>>>     description="Well detailed description what this law does.",
>>>     rules=(
>>>         LineReplaced(
>>>             name="Replace typo using regex",
>>>             path=Path("./gunicorn.conf.py"),
>>>             text="keepalive = 65",
>>>             target=r"^kepalive.*",
>>>         ),
>>>     )
>>> )
>>>
>>> pillar = Pillar()
>>> pillar.register(example_law)

Note

The indentation of the target text will be extracted by a simple regular expression. If a more complex regexp is required, please inherit from this class.

Warning

This rule will replace all the matching lines in the given file. Make sure the given target regular expression is tested before the rule used against production code.

YAML files

YAMLKeyExists

YAMLKeyNotExists

YAMLKeyRenamed

YAMLValueExists

YAMLValueNotExists